from/to date filtering in backend filterer/rummager

Fixed not_quite_as_fake_search_test and mysql tests.

NB: I found out that not_quite_as_fake_search_test will not run in
isolation with fast_test_helper

There is one slight problem we have lost the direction parameter now -
so assuming documents.in_reverse_chronological_order is the default
Fixing javascript tests
use chronic for date parsing
Display the date filters used

calling the date field date_ from/to as to_date is a reserved.

Fix filters

Update tests to use Chronic and new formatting
Use implicit hashes in method calls.
Use parens in method calls when returning a value.
Merge pull request #920 from alphagov/52381589-filter-by-date-range-elliotcm

52381589 filter by date range
Merge pull request #906 from alphagov/52381589-filter-by-date-range

Ability to filter the document lists on frontend by date range not before/after

https://www.pivotaltracker.com/story/show/52381589